The application comprises a device for protecting against water ingress and fire penetration into interspaces and into cavities through expansion joints in structures, cable ducts and cable lead-throughs which are occupied by cables and/or pipes, and, depending on the application, serves as a fire protection or leakage protection device in landfills, tank systems and transport and/or safety containers in the sea sector. The device comprises a flat-tube cushion which is fixed in terms of length and width and which is equipped on the outer sides with a swellable nonwoven sealing strip. In the interior, the leakage or protective flat-tube cushion is provided with at least one swellable nonwoven sealing strip which has high-tensile-strength closures on the longitudinal side and the transverse side and is filled or evacuated via at least one plastic-coated metal compressed-air valve with a valve extension, and, depending on the application, can be equipped with a radio monitoring or control system.